Jérôme Bibette

Layer-by-layer surface modification of lipid nanocapsules

Lipid nanocapsules (LNCs) were modified by adsorbing sequentially dextran sulfate (DS) and chitosan (CS) on their surface by the layer-by-layer (LBL) approach. Tangential flow filtration (TFF) was used in intermediate purifications of the LNC dispersion during the LBL process. The surface modification was based on electrostatic interactions between the coating polyelectrolytes (PEs) and the LNCs. Therefore, a cationic surfactant, lipochitosan (LC), was synthesised by coupling stearic anhydride on chitosan, and the surface of LNCs was first modified by this LC by the post-insertion technique. The PEs could be successfully adsorbed on the LNC surface as verified by alternating zeta potential and increase in size. To present a therapeutic application, fondaparinux sodium (FP), a heparin-like synthetic pentasaccharide, was introduced on the LNC surface instead of DS.

CHAPTER 10:Artificial Flagellar Micro‐swimmers

In this chapter, we will show how magnetic colloids can be readily self‐assembled into flexible magnetic filament structures. Due to their magnetic and flexible properties, applying external fields can deform these objects. The induced deformations are strongly reminiscent of flagella movements that are encountered in nature. Based on this observation of artificially induced flagella motion, we were able to use these filaments as artificial flagella, which can move in their surrounding viscous fluid and even carry a cargo. These engines were also used to confirm previous predictions made by scientists in the field of fluid mechanics.